include/linux/prime_numbers.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef __LINUX_PRIME_NUMBERS_H
0003 #define __LINUX_PRIME_NUMBERS_H
0004
0005 #include <linux/types.h>
0006
0007 bool is_prime_number(unsigned long x);
0008 unsigned long next_prime_number(unsigned long x);
0009
0010 /**
0011  * for_each_prime_number - iterate over each prime upto a value
0012  * @prime: the current prime number in this iteration
0013  * @max: the upper limit
0014  *
0015  * Starting from the first prime number 2 iterate over each prime number up to
0016  * the @max value. On each iteration, @prime is set to the current prime number.
0017  * @max should be less than ULONG_MAX to ensure termination. To begin with
0018  * @prime set to 1 on the first iteration use for_each_prime_number_from()
0019  * instead.
0020  */
0021 #define for_each_prime_number(prime, max) \
0022     for_each_prime_number_from((prime), 2, (max))
0023
0024 /**
0025  * for_each_prime_number_from - iterate over each prime upto a value
0026  * @prime: the current prime number in this iteration
0027  * @from: the initial value
0028  * @max: the upper limit
0029  *
0030  * Starting from @from iterate over each successive prime number up to the
0031  * @max value. On each iteration, @prime is set to the current prime number.
0032  * @max should be less than ULONG_MAX, and @from less than @max, to ensure
0033  * termination.
0034  */
0035 #define for_each_prime_number_from(prime, from, max) \
0036     for (prime = (from); prime <= (max); prime = next_prime_number(prime))
0037
0038 #endif /* !__LINUX_PRIME_NUMBERS_H */